1. Field of the Invention
This invention relates to clutch modules, especially for motor vehicles.
2. Description of Related Art
As is well known, a clutch module comprises, as a unit, a mechanism, a clutch friction wheel and a flywheel, with the mechanism itself comprising a cover plate having a side wall, a diaphragm which engages on the cover plate, and a pressure plate on which the diaphragm engages.
The invention is concerned more particularly with the case ill which, as is described for example in the document FR-A-2 546 594, the flywheel is constituted by a reaction plate which is similar to the pressure plate, and a support plate on which the cover plate of the mechanism is secured.
One of the problems to be overcome in the manufacture of clutch modules of this type is to obtain, for a given diametral size and/or total weight, a maximum inertia in order to increase the ability to absorb cyclic irregularities in the rotating mode.
An object of the invention is to provide a clutch module in which this inertia is optimised in a very simple manner, and which also has other advantages. This clutch module, which is of the above type, is characterised in that the pressure plate is thicker at its outer periphery than at its inner periphery, and in that the pressure plate and the reaction plate have from place to place, in slots formed locally in at least the side wall of the cover plate, radial peripheral lugs to which circumferentially elongated tongues are attached by fastening means, with the peripheral edge of the pressure plate extending over a circumference, the diameter of which is greater than the diameter of the circumference on which the fastening means for the tongues are located.
In this way, the inertia can be increased for a given diametral size, and the centre of gravity of the transverse cross section of the pressure plate is beneficially moved radially towards the outer periphery, to the benefit of its inertia.
The same is clearly true for the reaction plate, having regard to its similarity to the pressure plate.
Consequently, for a given inertia, the diametral size can beneficially be reduced. In order to reduce this diametral size still further, according to the invention the diameter of the circumference on which the fastening means for the tongues are located is smaller than the internal diameter of the side wall of the cover plate, and the tongues extend radially close to the outer portion of the clutch friction wheel.
The said tongues extend over an arc of a circle in order to reduce the size.
The similarity between the reaction plate and the pressure plate also leads to advantageous simplification of manufacture.